P- serve



(No Model.)

J.' P. SERVE.

BOILER TUBE.

UNITED warns,

JEAN PI EERJE SERVE,

OF GIVOR-S, FRANCE.

BOILER-TUBE.

' SPECIFICATION forming part of Letters Patent No. 349,060, dated September 14, 1886.

Application filed February 6, 1886. m-i=1 3T0. .iitflfri.

(No model.) Iainnlell in France Scpiemher20,1S8 I, No. 164,412.

To all whom it nutty concern.-

Be it known that I, J nan PIERRE SERVE, L citizen of the Republic of France, residing at (livers, in the said Republic, have invented a new and useful Improvement in Metallic Tubes for Steam Boilers and Condensers, of which the following is a specification, reference being had to the accompanying drawings.

The object of my invention is to increase the capability of transmission of heat, and also to increase the rigidity of the tubes without proportionately reducing the area of the tubes intheir transverse section. I obtain this result by constructing or providing the tubes with longitudinal solid and massive wings or fins,-either internal or external to the tubes. Tubes with such wings or fins employed in surface-condensers present to the water of condensation the greatest heating-surface possible and to steam the greatest cooling-surface possible, and

in a boiler they present the greatest surface to the water and to the gases of cor :buation. rho same result is obtained by them in other apparatus for transmitting heat or cold. These wingsor fins may have a rectilinear f0rm-- that is to say, may be arranged along the tube; or they may be arranged spirally around the tube. The dimensions, the form, the position, and'the number of the said fins or wings are Variable, and they may be applied or provided on the tubes,whatever be the construction of the latter, by any known means of manufacture-that is to ,say, in certain cases the fins or wings may be obtained directly by the rolling of a sheet of metal which is to be afterward rolled up to form the tube. In other cases the wings may be obtained by folding the sheet. In. other cases they maybe applied after the completion of the tube; and in other cases yet they may be obtained directly in the operation of drawing the tube when that mode of manufacture is employed. The wings are, however, always solid and massive, as distinguished from concave-convex dates or corrugations.

My invention has for its principal advantages, first, the augmentation, in a very great proportion, of the transmission of heat by reason of the increase of the heating-surface, and consequently the diminution in aconsiderable degree of the expense of fuel; second, the incrcasedrigidity of the tubes, which permits the employment for their manufacture of certain metals which could not otherwise be used.

Figure 1 of the drawings represents a transverse section of a seamless tube with internal fins. Fig. 2 represents a transverse section of a seamless tube with external fins. Fig. 3 represents a transverse section of a seamless tube with internal and external fins. Fig. 4 is a transverse section of a seamed tube with internal fins. Fig. 5 is a transverse section of a seamed tube with internal and external fins; and Fig. 6 is a transverse section of a seamed tube with specially constructed internal and external fins.

Similar letters of reference desgnatc corresponding parts in all the figures.

As may be seen by reference to the draw ings in the examples represented by Fig. 1, 2, and 3, the seamless drawn tube and the fins are obtained directly by the drawing operation. They may be only, as at a, in the in-- terior of the tube 1), Fig. 1, or they may be only on the exterior, as at c, Fig. 2, or both, as at a and c, in the interior and on the exterior, Fig. 3.

In the examples represented in Figs. 4, 5, and 6 the tubeis seamed-that is to say, formed of a sheet or strip of metal, I), rolled and soldered in the joint (I. In Fig. 4 the fins are simply constituted by folds a, all formed onsame side of the sheet 12, and of which the two thicknesses are soldered one to the other at e, as in the joint (1 of the tube. These folds are obtained by any mechanical means, and may be arranged either on the exterior or in the interior of the tube.

In the example shown in Fig. 5 the fins are formed of folds, as'has been described, and placcd'in the interior and on the exterior of the tube. Instead of being juxtaposited, as seen in the last-mentioned figure, the interior and exterior folds may be separated a certain distance.

In Fig. 6 I have represented an examp e in which the fins are both internal and external and formed of folds a, arranged in the inte" rior of the tube,as before described,but wider, and into this .I introduce bandsf, formed t enter the said folds and to project therefrom to form the external fins, the said bands being IOO soldered ate to the sides of the fold. The

fins may also be constituted by bands simply I applied and soldered or riveted upon the wall of the tube, the tube itself being in such case either seamless or seamed.

The fins may have any forms and dimensions whatever. They may be arranged on the tube in any manner whatever, and obtained on the sheets of metal either before or after the formation of the tube, or directly by the drawing of the tnbe,whethcr the tubes are seamless or seamed.

I am aware that tubes have been made with a corrugated or undulating profile in their transverse section, thereby securing a cour paratively slight increase in their radiating- Surface, and with almost a corresponding re duction in the area of their transverse section,

nil I do not include such a tubein myiuven tion. My tube is distinguished from those which have been before made in having, solid and massive wings which, when on the interior surfaces, project to a considerable dis tance into the tube and receive heat from the hottest gases which pass through the tube, and, whether upon. the interior or exterior surface, such wings very greatly increase the heatingsnrface of the tube and reduce but very little the transverse area of the tube-passage. By the solid and massive wings the interior or exterior heating-surface, or both, may be doubled or trebled without any proportionate reduction of the areal in transverse section, although, of course, the area will be slightly reduced by the interior wings.

What I claim as my invention,and d .zSllG to secureby Letters Patent, is-

1. The tube herein described for boil ers and condensers, having solid and massive wings upon its surface or surfaces, as distinguish d from a tube having awavy, corrugated vvor nu dnlating profile in transverse section, substantially as herein set forth.

2. The tube herein described for boilers and condensers, having its metal folded closely upon itself to form solid and massive wings upon its surface or surfaces, substantially as herein set forth.

3. The tube herein described for boil s and condensersdiaving its metal folded upon itself to form wings upon one surface, and having strips or pieces j" inserted within SUCK folds and projecting beyond the other surface. whereby are produced solid and massive wings projecting from both surfaces of the tulie, snlr stantially as herein described.

In testimony whereof I have sign d this specification in the presence of two subscribing witnesses.

JEAN PIERRE SE1" VE.

\Vi tnesses: F. J. Rsmrono,

N. HALL, Jr. 

